Solar shingles have been available for more than a decade. The installation of most of the solar shingle systems on the market today are very labor intensive. With most systems, it is necessary to first prepare the roof for the installation of the shingles. This may include placing a protective layer or water-resistant material on the roof surface. Structural features may also be installed on the roof in order to mechanically connect the shingles to the roof. These structural features may include some kind of rack or channel that the shingles attach to. These racks or channels must be physically attached to the roof structure. Typically, this requires a penetration through the water-resistant material and roof sheathing with screws or some other attachment mechanism. Every penetration may create a potential for future leaks in the roof.
For traditional solar shingle systems, once the structure is in place to support the shingles, the electrical wiring must be provided to each of the shingles. Typically, each shingle is “daisy-chained” together with adjacent shingles in the same row, connecting a row of shingles in series. At the end of each row there is normally a junction box that combines multiple rows of shingles and runs the combined power of these multiple rows of shingles to an electrical distribution system via an electrical power panel in the house or building.
The connection of shingles to adjacent shingles is normally done by connecting a shingle with an MC4 connector that provides a watertight electrical connection between two adjacent shingles. The row wiring at the end of each row of shingles typically has a junction box that combines multiple row wiring runs together, then has a combined home run back to the service panel. These steps typically require a significant amount of labor.
Many solar roof shingle systems consist of a series of solar shingles connected together either in series or in parallel. They are normally connected by wires with male and female connectors on either side of the wiring that connects the shingles. The wiring is either run along the backside of the shingles along a mounting rack, or along the inside of the back frame of the shingle itself. In some cases, the wiring is run inside a wiring chase or raceway behind the shingles.
In some cases, the shingles are applied directly to the roof surface. In other cases, a support structure is attached to the roof that provides a raceway for interconnecting wiring between the shingles. In every case it is necessary to electrically connect each solar shingle to an electrical circuit that distributes the electricity produced by the solar shingles to an electrical circuit.
Alternatively, the connecting wiring for multiple shingles may be integrated within the shingle itself, as described in patent application Ser. No. 15/261,160 submitted 9 Sep. 2016, entitled “Photovoltaic Modular System”. When the wiring is integrated or embedded within each of the shingles in the system, there still is the need to connect the wiring from the shingles to the electrical panel or devices being served by the shingles. It is also necessary to structurally attach the shingles to the roof.
Solar power systems are typically mounted in a location facing the sun in order to maximize the exposure to solar energy. However, there can be obstructions to the direct sunlight needed to power the solar panels. Clouds, trees, and architectural features or building elements can cause shading. Even partial shading of the solar panel can dramatically reduce the power output since the electron flow inside the panel is in series. Shading of only one section or portion of the solar panel will block the flow for the entire panel or group of panels.
Traditional solar power systems normally include multiple solar panels that are connected to each other by either parallel or series wiring (or a combination of both).
Prior to the introduction of microinverters, most if not all solar power systems were wired in series, having several “strings” of panels (a group of many panels, circuited in series), with each string feeding into a large power inverter that converted the DC power to AC power. The main disadvantage of this design is the fact that if there is shading on even one single panel within the string, it affects the current flow of that entire string (because they are wired in series) and reduces the total string power output to the lowest electrical current flow restriction created by the shading of that one panel.
For many solar shingles, a junction box or other similar equipment, connectors or parts are required for the connection to the power circuits that extend back to an electrical service panel. The connection to the interconnecting wiring with wire nuts or connectors and installing junction boxes requires a lot of time and labor.
In addition to the electrical connections, there is also needed a system to attach the shingles to a structure such as a roof structure. In some systems, the shingles are attached to the roof with adhesive or otherwise physically attached by nails or screws.
It is known that many solar shingles that are attached directly to the roof surface are not as efficient because of heat buildup. Many of the traditional systems do not provide a pathway for air to be transmitted behind the shingles and out of the top ridgeline of the roof to allow for naturally cooling of the shingles.